import java.io.*;

public class SharedObject implements Serializable, SharedObject_itf {
	
    // invoked by the user program on the client node
    public void lock_read() {
    }

    // invoked by the user program on the client node
    public void lock_write() {
    }

    // invoked by the user program on the client node
    public synchronized void unlock() {
    }


    // callback invoked remotely by the server
    public synchronized Object reduce_lock() {
    }

    // callback invoked remotely by the server
    public synchronized void invalidate_reader() {
    }

    public synchronized Object invalidate_writer() {
    }
}
